The present invention relates to an apparatus for recording compressed video and audio signals on a medium such as an optical disk or the like and reproducing such signals from such a medium.
A compression of video and audio signals has been described in detail in Jun Yonemitsu (editorial supervisor), “MPEG Technique,” pp. 19-21, published in Japan by Trikeps on Dec. 21, 1993. An example of an optical disk has been described in detail in Kenji Hayashi (editor and author), “CD-From Audio to Personal Computer,” pp. 84-89, published in Tokyo, Japan, by Corona Publishing Co., Ltd., on Jul. 25, 1990.
A compression method of the video and audio signals and a corresponding decompression method have been described in the first reference listed above. A signal recording format of a compact disc (CD) has been described in the second reference listed above. However, a method of easily realizing a retrieving method when the compressed video and audio signals are recorded on a medium and are reproduced therefrom is not described.
In the case of reproducing the medium such as a CD or the like on which the compressed video and audio signals have been recorded in a data stream format as described in the “MPEG Technique” reference listed above, a picture or a boundary of a group of pictures can be judged by reproducing the data stream and judging header information of a pack and a packet. In the case of recording a signal on the medium, however, in order to improve an error resistance, an interleave process and an error correction encoding process which are peculiar to the medium and a frame forming process involving addition of a sync signal and sub information are ordinarily executed. When the picture or boundary of the picture group is judged by reproducing the data stream and judging the header information of the pack and the packet, therefore, a position of a pickup or the like which is reproducing data from the medium has already been deviated. Therefore, in the case of performing a retrieval, an editing operation, and the like on a picture or picture group unit basis, a complicated control is needed to find a position of the picture or boundary of the picture group on the medium, so that there is a problem such that it takes a long time to find the position.